Telephone-receiver.



PATENTED MAY 3, 1904.

J. I. GEMMILL.

TELEPHONE RECEIVER.

rrmoumn rman 1120.22. 1002.

I0 IODEL.

W/ TN E SSE S g:

are. 759,095.

ll'NiTnn STaT s Patented May 3, 1904.

PATENT OFFICE.

TELEF-"W'IOINIE-IREKIDEIVER.x

SPECIFICATION forming part of Letters Patent NO. 759,095, dated May 3, 1904. Application filed December 22, 1902. Serial. No. 136,280. (No model.)

To all 11 7101 12. 712 may concern:

Be it known that I, Janus I. UEMMILL, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain THIPI'OVGIIIQDtS in Telephone-Receivers, of which the following is a specification and together with the accompanying drawings should make clear all the important features to those skilled in the art to which this appertains.

The object of my invention is to obtain a fixed adjustment between the diaphragm and the exposed poles of the electromagnets,so that the adjustment will remain normal throughout the use of the instrument.

Figure 1 shows a central longitudinal sec- "tion of receiver with the interior parts in their proper position. Fig. 2 is a section of the pressed-metal cup and block attached thereto. Fig. 3 shows two views of block 2, one-a section and the other an elevation. Fig. 4 shows two views of the electroinagnet-spools. Fig. 5 shows two views of type-metal block. Fig. 6 shows two views of threaded clevis used to hold the whole combination together in the hard-rubbershell. Fig.7 shows dijll'erentviews of the hard-rubber block which is used to sustain and insulate the soldered electrical connections one from the other.

In all the cuts in the drawings the same charactors of reference indicate similar parts.

In Fig. l I show a pressed-metal cup 1, to which is attached a brass block 2 by means of screws 3 8, of which only one is here shown. Aglance at Fig. 2 will clearly show how said block 2 is attached to said cup 1. Referring back to Fig. 1, the electromagnet-spools 1 4 and their respective cores 4 1 are passed through slots conveniently arranged in the bottom of said cup 1. Said cores are permanently attached to the block 2 by screws at 5 5. The exposed poles of the electromagnets at 6 6 are now lapped down, so as to come into a state of parallelism with and below the plane of the edge of cup 1, thereby creating the adjustment between the diaphragm 7 and the cores 6 6. The permanent magnet 8 is so bent and adapted to slip over the lower extremities of the electromagnet-cores and attached to same by a bolt 9, passing through the cores 4 t and the intervening brass block 2. in the bend oi the permanent magnet 6 at the point a is a type-metal block 19, so formed as to neatly lill said bend and through which is drilled a hole adapted to receive a bolt 10, which serves to attach the clevis 11. The said clevis sustains the hard -rubber block 12, which is held in place by means of pins through holes 13 13. Said clevis is drilled internally at the lower end, forming a channel 14, which serves to allow the introduction of connecting-wires to the system to which the instru ment is attached. The clevis is threaded extcriorly (shown at 15, Fig. 6) and is adapted to engage a thread in the rubber shell 16 at 17, and thereby, due to the flexibility oi" the joint at (I, will draw into perfect alinement the whole combinathim in the shell 16. strain is taken up by the aforementioned pressed-metal cup 1, it resting on the shell 16 at or about the points 66 7) I).

The diaphragm '7 rests on the edge of cup 1 and is held in place by the hard-rubber cap 18 engaging the shell 16 by means of a thread at 20. The hard-rubber block 12 serves to attach the solder-clips 18 18 to.

The leading-in wires and cord connections are not shown, as they do not enter into or in any way interest in this case and would only tend to obscure the drawings.

Having now fully described my invention, what I claim as new, and wish to secure by Letters Patent, is

1. In a telephone receiver a metal cup, in combination with a metal block, electromagnet-spools attached thereto and a permanent horseshoe-magnet secured to the block and e1ectromagnet-spools, a clevis with a threaded shank and a metal block attached to said permanent magnet, together with a hard-rubber block, supporting the solder-connecting clips, all as shown and described.

2. In a telephone-receiver, in combination, a suitable metal cup, a magnetic insulatingblock attached thereto, electromagnet-spools attached to said block and a horseshoe-magnet secured to said block and spools, a suitable metal block and clevis with threaded shank,

The

secured to said magnet and a suitable ruhher to this specification, this 8th day of December, casing, with an interiorly-threuded hole in the A. D. 1902, in the presence of two subscribtailpiece, through which the threaded shank of ing Witnesses.

the clevis passes and secures the several parts J AMES I. GEMMILL. 5 Within the shell, substantially as shown and WVitnesses:

described. JAMES R. GEMMILL, S11,

In testimony whereof I have affixed my name LEOTA M. GEMMILL. 

